PEQ: Graph should reflect Q value for shelf filters

[harkpabst]

The PEQ feature in WiiM's products has developed very well over time and definitely turned into an extremely powerful tool. One great feature is the support of fully flexible filter Q values, not only for peak filters, but also for high shelf and low shelf filters.

Unfortunately, the effects of different Q values are currently displayed for peak filters, only.

For example, here are the graphs for a 200 Hz +10 dB PK filter with either Q=1.5 or Q=0.15. The difference is obvious and understood very intuitively.





In contrast, the graphs for a 200 Hz +10 dB LS filter currently look exactly the same for Q=1.5 and Q=0.15. But this is not what really happens.





My request is to visually display the effect of different Q values for shelving filters as well.

For the LS filters shown above this should look somewhat like this:




Although I am well aware of the fact that precise measurements should ideally be combined with listening experience, this would be a more than welcome improvement.

Please upvote if you agree, please comment if you don't.

 

[Wiimer]

The PEQ feature in WiiM's products has developed very well over time and definitely turned into an extremely powerful tool. One great feature is the support of fully flexible filter Q values, not only for peak filters, but also for high shelf and low shelf filters.

Unfortunately, the effects of different Q values are currently displayed for peak filters, only.

For example, here are the graphs for a 200 Hz +10 dB PK filter with either Q=1.5 or Q=0.15. The difference is obvious and understood very intuitively.

View attachment 7290
View attachment 7291


In contrast, the graphs for a 200 Hz +10 dB LS filter currently look exactly the same for Q=1.5 and Q=0.15. But this is not what really happens.

View attachment 7296
View attachment 7297


My request is to visually display the effect of different Q values for shelving filters as well.

For the LS filters shown above this should look somewhat like this:

View attachment 7298
View attachment 7299

Although I am well aware of the fact that precise measurements should ideally be combined with listening experience, this would be a more than welcome improvement.

Please upvote if you agree, please comment if you don't.

I couldn't agree more.
That was exactly the discomfort I was feeling today while playing with the PEQ LS.

Thanks for the heads up.

 

[MrSoul4470]

Is the Q factor maybe fix for shelf filters?

 

[harkpabst]

Is the Q factor maybe fix for shelf filters?

As you can see from the screenshots it can be configured in the WiiM Home App.

Also measurements performed by @Wiimer (when trying to simulate the still missing low pass and high pass filters using shelf filters) did clearly show the expected overshoot when increasing the Q value. In his case this was highly undesirable.

Issues with the LS and HS in PEQ?

I'm off today, so I'm testing the WiiM pro and Mini with MRM. So, I seem to have found some issues with PEQ. I used LS and HS on PEQ to connect the Pro to the main speakers and the Mini to the subwoofer to set up the crossover. However, when LS and HS are set to their maximum values, they...

forum.wiimhome.com

I think we know for sure that the Q factor is not fixed.

 

[Musician]

As you can see from the screenshots it can be configured in the WiiM Home App.

Also measurements performed by @Wiimer (when trying to simulate the still missing low pass and high pass filters using shelf filters) did clearly show the expected overshoot when increasing the Q value. In his case this was highly undesirable.

Issues with the LS and HS in PEQ?

I'm off today, so I'm testing the WiiM pro and Mini with MRM. So, I seem to have found some issues with PEQ. I used LS and HS on PEQ to connect the Pro to the main speakers and the Mini to the subwoofer to set up the crossover. However, when LS and HS are set to their maximum values, they...

forum.wiimhome.com

I think we know for sure that the Q factor is not fixed.

Agree , they should fix the display and show the overshoot with different Q values.
However , a variable Q using shelving filtering with overshoot is a very useful tool , so it shouldnt be limited to higher values than Q=1.

As it is, the possibility to use higher Q values with shelving is one of the best things with the WiiM streamers. To get better bass, for example:

https://audioxpress.com/files/attachment/2721

 

[harkpabst]

Agree , they should fix the display and show the overshoot with different Q values.
However , a variable Q using shelving filtering with overshoot is a very useful tool , so it shouldnt be limited to higher values than Q=1.

I explicitly do not request to introduce a fixed Q of 0,707 or whatever value (even if that would ensure that display and reality match up). I want to keep variable Q shelving filters, just please fix the display, WiiM.

 

[Chris Bolkan]

Just received my Wiim Ultra. For my setup I need both low and high shelving filters. I could NOT figure out what was going on when I changed Q value on shelving filters when other filter displays behaved as expected. Until I dug up this thread. Happy to see it is just a display of information bug. However, it is annoying. Would love to see it corrected. Thanks!

 

[harkpabst]

Just received my Wiim Ultra. For my setup I need both low and high shelving filters. I could NOT figure out what was going on when I changed Q value on shelving filters when other filter displays behaved as expected. Until I dug up this thread. Happy to see it is just a display of information bug. However, it is annoying. Would love to see it corrected. Thanks!

I hope you did hit that upvote button.

This might just be seen as a visual flaw, but it's certainly very misleading.

 

[Chris Bolkan]

I hope you did hit that upvote button.

This might just be seen as a visual flaw, but it's certainly very misleading.

 

[canard]

already said but, allowing full screen , serious mathematical approch, and showing the reality of the overruns etc, not a truncated vision, would be welcome....
in the absence of autogain...will allow us to more accurately understand the negative gain to be applied for the vast majority of people

 

[Chris Bolkan]

Hi!

Apologies if this is a newbie question that has already been hammered to death.

Reading this thread got me wanting to visualize Q settings and their effect on overshoot when using shelving filters with the Ultra. I only have minimum exposure to them. I found some nice descriptive graphs, but they got me wondering how the frequency of a shelving filter is defined. I assumed it was the 3 dB point where the filter started moving more aggressively towards it's final level, just like a normal filter cutoff is defined. However, looking at the graphs I found on line, it looks like it is the center frequency of the filter.

How is the frequency of a shelving filter defined? A 3db point or center frequency? The graphs below indicate center frequency.
How does WiiM define the frequency in their implementation?

The answer has a significant effect on how I choose the shelving frequency.

Thanks!

Chris

 

[slartibartfast]

Hi!

Apologies if this is a newbie question that has already been hammered to death.

Reading this thread got me wanting to visualize Q settings and their effect on overshoot when using shelving filters with the Ultra. I only have minimum exposure to them. I found some nice descriptive graphs, but they got me wondering how the frequency of a shelving filter is defined. I assumed it was the 3 dB point where the filter started moving more aggressively towards it's final level, just like a normal filter cutoff is defined. However, looking at the graphs I found on line, it looks like it is the center frequency of the filter.

How is the frequency of a shelving filter defined? A 3db point or center frequency? The graphs below indicate center frequency.
How does WiiM define the frequency in their implementation?

The answer has a significant effect on how I choose the shelving frequency.

Thanks!

ChrisView attachment 14741View attachment 14742

Centre frequency makes most sense to me. How would you define a -3dB frequency for a 2dB shelf filter?

 

[Chris Bolkan]

Good point. Thanks for the perspective! That's what I'll go with.

 

[canard]

the problem is that the graphic presentation that wiim offers is too crude and mathematically not fair....
we are inevitably tempted to be proud... leads to many misunderstandings of the problems encountered etc.

 

[harkpabst]

the problem is that the graphic presentation that wiim offers is too crude and mathematically not fair....
we are inevitably tempted to be proud... leads to many misunderstandings of the problems encountered etc.

Discussions aside, this is exactly why I made this very feature request. See post #1.

 

[canard]

i know...

 

[slartibartfast]

Discussions aside, this is exactly why I made this very feature request. See post #1.

More than six months later it still isn't fixed. It isn't even really a feature request it is a request to fix a bug. Was it ever reported via feedback in the app?

 

[Wiimer]

the problem is that the graphic presentation that wiim offers is too crude and mathematically not fair....
we are inevitably tempted to be proud... leads to many misunderstandings of the problems encountered etc.

Do you wish to improve the display of the entire graph, not just the shelf filter? For example, would you like to be able to view a graph in full screen at a higher resolution?
...
Nevertheless, it is very disappointing that this issue has not been corrected after 6 months.

 

[canard]

Do you wish to improve the display of the entire graph, not just the shelf filter? For example, would you like to be able to view a graph in full screen at a higher resolution?
...
Nevertheless, it is very disappointing that this issue has not been corrected after 6 months.

technically joins the more serious absence of intelligent auto gain which has existed for more of 2 and a half years....
but hey there is the choice of clock on the ultra screen...
;-)
before stacking functions see enough annex.. it is good to make the current ones see essential "finished"
no?

 

[canard]

Do you wish to improve the display of the entire graph, not just the shelf filter? For example, would you like to be able to view a graph in full screen at a higher resolution?
...
Nevertheless, it is very disappointing that this issue has not been corrected after 6 months.

the classic subject autogain seems inexhaustible to inges wiim or subcontracting...
a mathematically correct representation, see full screen HD would allow everyone a correct manual approach, help, to gain adaptation...